check_pull_request_title.yml

name: "Check PR title"

on:
  pull_request:
    types: [edited, opened, synchronize, reopened]

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
  cancel-in-progress: true

permissions:
  contents: read
  pull-requests: read
  statuses: write

jobs:
  pr-title-check:
    runs-on: ubuntu-latest
    timeout-minutes: 5
    if: ${{ github.event.pull_request.user.login != 'allcontributors[bot]' }}
    steps:
      - uses: amannn/action-semantic-pull-request@v5.5.3
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          # Require imperative mood (e.g. "Add feature" not "Adds feature")
          # ^                       Start of string
          # [A-Z]                   First character must be an uppercase ASCII letter
          # [a-z]*                  Followed by zero or more lowercase letters
          # (?<![^s]s)              Negative lookbehind: disallow single 's' at end of first word
          # ( .+)+                  At least one space and one or more characters
          # [^.]                    Final character must not be a period
          # $                       End of string
          subjectPattern: '^[A-Z][a-z]*(?<![^s]s)( .+)+[^.]$'
          subjectPatternError: |
            The PR title must use imperative mood and proper formatting:
            - Start with uppercase letter (e.g., "Add" not "add")
            - Use base form of verb (e.g., "Add" not "Adds" or "Adding")
            - Have multiple words (minimum 10 characters)
            - Not end with a period

            Valid: "Add new feature", "Fix bug in parser"
            Invalid: "add feature", "Adds feature", "Add.", "Fix"
          # Disable type prefixes (we don't use conventional commits format)
          requireScope: false
          ignoreLabels: |
            ignore-title-check